1. Field of the Invention
The present invention relates to a motorcycle rear fender structure secured to a motorcycle frame structure above a motorcycle rear wheel.
2. Description of the Prior Art
In some of the motorcycles now in use, a rear frame substructure forming a rear portion of the motorcycle frame structure is generally provided with a rear wheel fender positioned above the rear drive wheel, a tail cover for covering an outer region of the rear frame substructure except for the position, where a driver's seat or a driver's seat and a fellow passenger's seat are installed, to provide an appealing appearance, and a storage space positioned below a fellow passenger's seat and including, for example, a glove box, a tool box and/or a casing for accommodating electric components. In general, the glove box and the tool box make use of the rear wheel fender as their bottom surfaces, of a top opening of the tail cover as an access opening and of the seat as a lid for those boxes. See, for example, the Japanese Laid-open Patent Publication No. 2004-224176, published Aug. 12, 2004.
In order to stably support various component parts of the motorcycle such as, a battery and/or an electronic control unit, the rear wheel fender is desired to have a bottom wall provided with fixing walls and hooks. Consequently, the rear wheel fender tends to take a relatively complicated rugged configuration and is generally manufactured as a resin molded article.
However, considering that the rear wheel fender is so shaped and so designed as to prevent water and/or mud, splashed from the motorcycle rear wheel, from entering an interior space inside the rear wheel fender, it is a general notion that the bottom wall of the rear wheel fender cannot have a design with perforations defined therein. Therefore, the rear wheel fender, when being manufactured by means of a plastic molding technique together with the fixing walls and hooks, must be molded with the use of a mold assembly having no shaped elements, which would leave mold holes in those portions of the molded product (i.e., the rear wheel fender) where such fixing walls and hooks are formed. In view of this, when it comes to the molding of the rear wheel fender, the use is considered essential of a two-piece mold assembly including upper and lower molds of a complicated shape having cores and sliders defined in each of the upper and lower molds. This does indeed lead to reduction of the productivity and increase of the manufacturing cost.